A system that can detect when abnormal trading activity is occurring and take action to halt the detected abnormal trading activity without human intervention using a computer-implemented anomaly detection and action stage that performs an exponential weighted averaging of trade order flow, on a per symbol basis within a sliding volume based window and a volume based exponential weighted averaging, on a per symbol basis, on trade update messages received during the sliding volume based window and checks for an inflection in covariance between them. A related method is also described.